Conventionally, as a battery mounted in an electrically driven vehicle such as a hybrid or electric vehicle, a battery pack or assembly is known, which is formed by combining a plurality of battery modules. The individual battery module is in turn constituted by connecting one or more unit cells wherein the unit cell represents a minimum unit or element of the battery. For example, as the unit battery, such as a lithium ion secondary battery is used. The battery pack or assembly such as these is provided with a bus bar to connect unit cells or battery modules each other.
In such a conventional battery assembly, a method is used to monitor the temperature increase and the like due to heat generated during charge and discharge, according to which, by sensing the temperature of the bus bar by a temperature sensing element, the temperature of the battery assembly associated is equivalently detectable. Note that, for example in JP 2001-272422 A, it is disclosed that a temperature detecting element is provided on a bus bar disposed between vehicle electrical equipment and a battery terminal.